When a capacity of a nonaqueous electrolyte battery is increased, it is necessary to use an active material having a high capacity such as a compound having a high Ni content among lithium-containing nickel-cobalt-manganese composite oxides, to increase a density of an electrode, and to decrease an amount of auxiliary members in an electrode-mixture.
When the measures described above are carried out, however, though the increase of an energy density can be expected, a crystal structure of the active material is easily deteriorated, an electrical conduction network is insufficiently formed in an electrode-mixture layer to cause deviation in resistance distribution, low porosity of the electrode member layer and high likelihood of deviation in Li ion concentration, thus resulting in occurrence of a risk that long-term properties such as a cycle property is decreased.
It is required, accordingly, to find an electrode structure (a composition, a density, and an existential state of components) having both of a high energy density and an excellent cycle property.